Such assemblies are described in a broad array of design variations, for example, for use with two switches (EP 0 865 054 A2; EP 1 026 712 B1). For the most part, however, assemblies have been described for three switches (EP 0 853 324 B1, EP 1 204 127 A2, DE 195 08 808 C1). The fields of application for such assemblies arise, for example, where there are two separate grid connections, which, in the case of a fault, are replaced by an emergency power generator. The emergency power generator must not be able to be brought onto load when the grid connections are present and vice versa.
The existing assemblies are each conceived and designed for an intended purpose. Such assemblies are then not suited for a second purpose.
An assembly is described (German Examined Patent DE 44 09 172 C2) whereby a locking device for two switches is derived from a locking device for three switches. The locking device has a translationally and rotationally movable coupling element that can be used for the interlocking engagement of three switches in up to seven switch combinations.